14 replies to this topic

[ryanha]

Hi all!

 

In a recent image I noticed that there seemed to be a lot more hot-pixel type noise in my calibrated subs.  (you may have to click the image belowe to see full version to see it).

 

Fortunately this was integrating out (dithering to the rescue!). 

 

But I still was not happy with the fact that the noise was there in my subs and I started wondering if maybe my sensor was starting to go bad in someway.  Further investigation showed that it started happening right after I upgraded my driver (whew, software is easier to return to China than hardware).

 

I upgraded the driver because it unlocks native pixel resolution so what was a 4k x 2k (4.6u px) camera turned into an 8k x 4k (2.3u px) camera. I am not using this new native resolution at the moment, so I thought the only adjustment I would have to make is to change my 1x1 bin sequence to 2x2 bin sequence (to remain at the "old" native resolution of 4k x 2k).

 

When I examined DARK subs from the old driver vs. the new driver it turns out that the new driver is actually less noisy than the old driver as measured by some image analysis tools, but even so it was producing these tiny subtle artifacts.  So I re-shot a set of DARKs for the image I was working on and it fixed the hot-pixel like artifacts!

 

So "fortunately" it is cloudy so I committed my camera for the last 18 hours to re-take my dark library

 

Just thought I would pass this along for other 294mm users.

 

 

Thanks,

--Ryan

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Edited by ryanha, 27 January 2021 - 09:10 AM.

[ryanha]

Also, today I learned that you can use WBP to bulk integrate a dark library.  E.g. just load up all the dark subs and leave light and flats tabs blank and it will integrate each of the dark sets by exposure time. 

 

Unfortunately since wbp does not differentiate on gain, Ill have to do this once for each gain setting, but that is fine.  I thought I was going to have to manually integrate each of these, so this saved a bunch of time!

 

Images below show my dark library sequence and a shot from WBP showing how the darks are automatically binned by exposure time.

 

--Ryan

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[khursh]

Thanks for the info Ryan. What are the dates of the old/new drivers?

[ryanha]

It was the 12/31/2020 driver I believe: link.

 

--Ryan

[khursh]

That's the one I am using. Thanks

[Dean J.]

Hi all!

 

In a recent image I noticed that there seemed to be a lot more hot-pixel type noise in my calibrated subs.  (you may have to click the image belowe to see full version to see it).

 

Fortunately this was integrating out (dithering to the rescue!). 

 

But I still was not happy with the fact that the noise was there in my subs and I started wondering if maybe my sensor was starting to go bad in someway.  Further investigation showed that it started happening right after I upgraded my driver (whew, software is easier to return to China than hardware).

 

I upgraded the driver because it unlocks native pixel resolution so what was a 4k x 2k (4.6u px) camera turned into an 8k x 4k (2.3u px) camera. I am not using this new native resolution at the moment, so I thought the only adjustment I would have to make is to change my 1x1 bin sequence to 2x2 bin sequence (to remain at the "old" native resolution of 4k x 2k).

 

When I examined DARK subs from the old driver vs. the new driver it turns out that the new driver is actually less noisy than the old driver as measured by some image analysis tools, but even so it was producing these tiny subtle artifacts.  So I re-shot a set of DARKs for the image I was working on and it fixed the hot-pixel like artifacts!

 

So "fortunately" it is cloudy so I committed my camera for the last 18 hours to re-take my dark library

 

Just thought I would pass this along for other 294mm users.

 

 

Thanks,

--Ryan

Thanks Ryan, that is helpful.

 

I just took delivery of a new ASI294MM Pro yesterday. 

 

I noticed that when connecting to the camera in SharpCap using the native driver the camera initializes in the 2x2 bin mode by default.  However, when connecting to the camera using the ASCOM driver in both SharpCap and in Sequence Generator Pro the camera initializes in the 1x1 bin mode by default.  There isn't a switch or setting on the settings window in SPG to default to the 2x2 bin mode [which is what I want to happen] nor can I figure out which of the driver settings on the ASCOM Profile Explorer I can change to have the camera initialize in the 14 bit 2x2 bin mode.

 

Is there any way to have the camera default to the 2x2 bin 14 bit mode when using the ASCOM driver?

Edited by Dean J., 29 January 2021 - 11:29 AM.

[ryanha]

 

Is there any way to have the camera default to the 2x2 bin 14 bit mode when using the ASCOM driver?

My understanding is that the binning mode is set by the controlling software (e.g. SharpCap), not by the driver.

In other words, when the software (like SharpCap) connects to the camera, it asks the camera to enumerate its modes and then the software tells the camera which mode to default to (not the other way around).

 

I just tested this out myself.  In SharpCap I connected to my 294mm and changed the capture setting, then exited SharpCap and then relaunched it and the previous setting was retained.

 

On the PC you can find this file in " %APPDATA%\SharpCap\CaptureProfiles "  (just press WIN-R then type that in and it will bring up the folder).

 

Another thing I checked out is that I connected to the camera using the ASCOM driver to see what settings are stored as defaults in the camera at it was only offset, gain, bit depth and USB limits (not binning).

 

Hope that helps!

 

--Ryan

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Edited by ryanha, 29 January 2021 - 01:50 PM.

[Dean J.]

Yes, SharpCap does open into the 2x2 bin mode automatically when using the native driver.  It doesn't do that for me when using the ASCOM driver.

 

I use SGP for my image capture and connect to my camera with the ASCOM driver.  When I connect up with SGP the camera is in the 12 bit 1x1 mode and I have to specify 2x2 bin for the capture. 

 

It just seems strange that the native driver defaults to 2x2 bin but the ASCOM driver defaults to the 1x1 bin.  I would prefer to have the ASCOM default be 2x2 as well.  I just haven't figured out how to do that yet.

[ryanha]

 

It just seems strange that the native driver defaults to 2x2 bin but the ASCOM driver defaults to the 1x1 bin.  I would prefer to have the ASCOM default be 2x2 as well.  I just haven't figured out how to do that yet.

Let me see if we are talking about the same thing.

 

In SharpCap, I connect to the 294mm with ASCOM driver.

The binning is set to 1x1 by default, so I change it to 2X2

Then I close SharpCap

 

Now I re-launch SharpCap and connect to the 294 with ASCOM driver

The binning is set to 2x2 by default

 

Are you seeing something different?

 

--Ryan

[Dean J.]

Yes, talking about something different.  :-)

 

I use SGP for image capture.  The camera opens in the 1x1 bin mode in SGP when using the ASCOM driver and this appears to be the default setting notwithstanding the fact that the ZWO product page for the camera states that the 14 bit 2x2 bin mode is the "default" mode for the camera.  So, the question is, why does the ASCOM driver default to the 1x1 mode?

 

I should make a new topic for this question.

Edited by Dean J., 29 January 2021 - 04:00 PM.

[ryanha]

Got it.  What I was getting at is that this is not a driver setting it is an app setting.

 

That is what I was demonstrating with the SharpCap example.

 

So the question is why does SGP default to 1x1 when you create a new capture.  NINA does the same.  Turns out that camera defaults are apparently hard to do (or at least that is what the NINA devs told me when I asked if there was a way to change the default sequence/capture to 2x2).

 

In NINA you can set the default offset and the default gain for capture but not the binning.  I accidentally made some 8k x 4x 1x1 binned subs before getting better at remembering to change it for my sequences.  Also in NINA you can create template sequences with 2x2  binning which is what I use now.

 

Thanks,

--Ryan

Edited by ryanha, 29 January 2021 - 06:50 PM.

[lucam]

Yes, talking about something different.  :-)

 

I use SGP for image capture.  The camera opens in the 1x1 bin mode in SGP when using the ASCOM driver and this appears to be the default setting notwithstanding the fact that the ZWO product page for the camera states that the 14 bit 2x2 bin mode is the "default" mode for the camera.  So, the question is, why does the ASCOM driver default to the 1x1 mode?

 

I should make a new topic for this question.

Dean,

 

Just a guess but SGP has no idea about the internal working of the ASI294MM. ZWO chose to write an ASCOM driver that uses two different on-chip binning modes (11M and 47M) as selected by the user with binning. In other words, bin 1x1 chooses 2.3um pixels, 47M output file, while bin 2x2 chooses 4.6um super-pixels with 11M output file. There is no provision for choosing to bin 2x2 in software the 2.3um (which would be a silly thing to do on this camera). This is why SGP has no clue about the internal working of this sensor and gives you a choice of binning just like with every other camera, which defaults to 1x1.

 

Conversely, QHY put the choice of 11M vs 47M in the ASCOM driver itself. SGP would not know that you chose the 11M or 47M mode. In that case, you would shoot at bin 1x1 in SGP regardless of which mode the camera is using. This would allow for the situation of choosing to software bin 2x2 the 2.3um pixels of 47M mode (again, something that is most likely not optimal on this camera).

 

The advantage of the ZWO implementation is that in the same target you can choose to shoot some events in 11M mode and some in 47M mode. Suppose you have a nebula with bright and detailed Ha signal but faint and diffuse OIII and SII, you could image Ha bin 1x1 and OIII and SII bin 2x2. The ZWO camera would use on-chip binning for bin 2x2, while I don't think this would be possible with the QHY camera.

 

--Luca
 

Edited by lucam, 30 January 2021 - 11:38 AM.

[Dean J.]

Dean,

 

Just a guess but SGP has no idea about the internal working of the ASI294MM. ZWO chose to write an ASCOM driver that uses two different on-chip binning modes (11M and 47M) as selected by the user with binning. In other words, bin 1x1 chooses 2.3um pixels, 47M output file, while bin 2x2 chooses 4.6um super-pixels with 11M output file. There is no provision for choosing to bin 2x2 in software the 2.3um (which would be a silly thing to do on this camera). This is why SGP has no clue about the internal working of this sensor and gives you a choice of binning just like with every other camera, which defaults to 1x1.

 

Correct.

 

Also, my version of SGP - Version 3 - does not let you use the native driver.  Using the native driver in SharpCap initializes the camera in the 2x2 bin mode... the mode described as the "default" mode in the product documentation.

 

There is a "HardBin" selector in the ASCOM driver which is set to "0".  I don't know yet what this selector will do.  I am assuming that "HardBin" means hardware bin but Google searches haven't shed any light on the subject yet.

[ryanha]

 

There is a "HardBin" selector in the ASCOM driver which is set to "0".  I don't know yet what this selector will do.  I am assuming that "HardBin" means hardware bin but Google searches haven't shed any light on the subject yet.

Can you send a screen shot of that?  I don't see hardbin in my ASCOM driver for the 294mm.

 

--Ryan

[Dean J.]

Using ASCOM profile explorer:

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